924Board.org

[Dave951M]

Well--- I saw a link somewhere, don't know if it was on this board, to an automotive page that listed a bunch of salvage ricer intercoolers and their relative effectiveness. I got stupid and forgot to bookmark it. Anybody have that link?

I saw an interesting intercooler from an RX7 that looked very promising and could even be made front mounted rather easily. Then all I have to do is mount a micro switch and rerout the washer tank to the intercooler for further cooling. Can't even think further without that LINK? Man getting old really bites.

Dave

[Peter_in_AU]

strangely enough the links are in the links section.

http://www.924board.org/viewtopic.php?topic=1403&forum=11&0&offset=601

[Peter_in_AU]

Dave, the intercooler from the RX7 is the one to go for. I just sold one yesterday (needed the cash for other things).

The best RX7 one is from the series 4 (second best is the series 5). It will fit easily in the nose. You could also top-mount one, they're top-mounted in the RX7.

The actual size of the S4 'cooler is 370mm wide (not counting the pipes which can be cut off and rewelded if needed) 320mm high and 80mm deep and the end-tank pipes are 48mm ID.

[Cbass]

To clarify, the series 4 is the FC3S Turbo 2, right? In other words, second gen RX7, 88-91?

[Peter_in_AU]

it's the one that looks like





The series 5 one looks like





The trick to telling the difference between the two is to measure the header pipes. On the S4 the pipes are both 48mm Inner Diameter and on the S5 one pipe is 48mm ID and the other is only 40mm.



Either is good it's just that the S4 is better. Of course, if you cut the end tanks off and add custom ones then as far as I know there is no difference in the cores. As for when the different RX7s came out, I have no idea. I prefer the original to the Japanese copy

[Dave951M]

Strangely enough Pete- THIS link wasn't in the links section. In searching for this link, I followed each link in order, did searches of both the Rennlist archives and this board. I guess my search parameters weren't quite correct. But, the link you put to the old thread was the one I'm looking for. Thanks for the info and there are a couple of salvage yards close that have quite a few imports in them, including Porsche.

[John H]

Just ask Rick what he thinks of a RX7 cooler.

They fit just fine on top of the motor.
Subject to core avaialblilty I can do you one that fits the 931 and all you have to do is remove the charge tube and fit the cooler.

Depending upon your car it is normally just a straight forward job - undo three bolts two hose fittings - fit the cooler do up three to four bolts a coupleof hose clamps and the same two hoses and you're away.

Cost to you guys around US$500 plus freight.

[Dave951M]

John, could you post a picture of your intercooler? The main reason I'm leaning on domestic fabrication is that you're literally half a world away. (Plus I just like to make stuff.) I can source a core at the local salvage yard for about $100US, making the plumbing is relatively simple. I've looked at those doing the 951 rout, and haven't seen too much posted about the results. I can lay my hands on a 951 unit, but for way more than a ricer, the bonus being less fabrication for the ricer to fit.

Dave

[dwak]

Dave, how does your 931 compare to the 951, performance wise? In acceleration and handling?
dwak

[Dave951M]

Couldn't compare, my 931 was towed home and is in the process of renewal, maybe gooder than before? I can tell you this, if you can find someone with a good running 951, try to get a ride in it. 0-60 in less than 6 seconds is quite a rush, and that's a stock one. One with some tinkering done, is a very fast car and I don't think a streetable 931 could stand up to a comparably prepped 951. Just my opinion thus far, but working to prove myself wrong.

[Rick MacLaren]

The '88 and '89 951's, what could be called the "S's", are out of our league, in my opinion. But I think the '86 through '87 951's might be fair game for many of us, if we throw some more cash at our cars in the right places.

A buddy of mine, who owns a 951, took mine out for a spin a couple of weeks ago. He wouldn't admit to whether or not my 931 would take his '87 951. He said the cars 'felt' way too different to compare, notably cause his spool up was so different, his was chipped, mine was way noisier, mine felt much rougher, I had unmatched tires, and the list goes on.

The best way to test would be on the track with a clock. If ya do the test, the 951 ought to smoke a 931 from 0 to 100 MPH.

However, 0 to 60 MPH might be challenging for the 951. The 931 has a very torquey ride in 1st and 2nd, or so it seems. If you rev to 5600 RPM in 1st (on my car at least), then change gears, there's no lag. Similarly, from 2nd to 3rd, change at 5500 RPM and there's no lag. Very quickly you're at 60 MPH. I think a slightly hopped 931 would not be embarrassed by the 951 in that RPM range.

Still, it seems to me the cars are close enough, at the lower ranges, that normal human judgement is potentially in doubt. Probably on the track the 951 should shine on track time and whup the 931, but ya might not be able to tell the difference in speed just by sitting in each car and going through the gears from 0 to 60 MPH.

My buddy, the 951 owner, did say my 931 could take a '75 911 S. The '75 911 S was the quickest normally aspirated 911 in that era (i.e., 0 to 60). So if true, that's not too shabby. It's certainly respectable. Still, that might just be because mine's had engine and other mods, so this may not apply to the stock vehicle.

I have to agree with Dave that a 'comparably' equipped 951 will smoke a 'comparably' equipped 931. However, good luck on finding two cars 'comparably' equipped when the cars have like between 4 and 8 years difference between them. I would speculate that, in Dave's case, his '82 could easily (with enough $, naturally ) be made to smoke numerous streetable '86 951's, but NOT an '88 S or '89 951 unless the driver of the later-model 951 was stoned.


[ This Message was edited by: Rick MacLaren on 2002-07-24 04:21 ]

[924RACR]

One of these days I will convince my neighbor to go down to Milan Dragway with me... me with my '82 931, him with his 89 951 Cab. Both are stock right now. Should be fun! LOL

_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[Dave951M]

Vaughn- isn't the whole purpose of a Porsche to be able to turn at the end of said dragway???

I would have to agree that they are very different feeling cars, 4 or so years of technology and changes in between guarantee that. That said, the lower end torque and gearing of the 931 of a somewhat built 931 will prove an ugly surprise to a lot of folks, ie ricers, rustangs and so on. Even to some 911 owners.

On that line, at a PCA meeting, one of the 911 owners,(a wealthy fender polisher) asked the question to me, in front of the entire table- So, what is a 951 and what makes it better or special over a 911? I didn't even have a chance to answer since a guy who races simply put it to him- don't never, ever mess with a 951 on the street since properly driven, it will hand most 911's their heads. With that bit of dramatic exageration, he proceeded to educate Mr. Fender Polisher about the finer points of stock and built 951s. My galant defender races 911s and 914s. I added some topping to our performance dessert by explaining the ease with which hp can be had from the 951 compared to the 911 and rubbed salt into the wound by pointing out a built 951 is cheaper than most 911s stock!

Maybe I just like poking the eye of the establishment, that's why I own the Rodney Dangerfield of the Porsche world and his bumpkin Audi cousin. That doesn't mean I don't like 911s, just that I march to a somewhat different Teutonic drummer.

Dave